It is well known that compositions containing at least 52% by weight of ethanol or isopropyl alcohol are antibacterial and, thus, widely accepted for disinfecting purposes.
Compositions with high alcohol content for disinfecting the hands are available as an antimicrobial alcoholic gel as described in U.S. Pat. No. 4,956,170 to Lee. While using gels to deliver an alcoholic disinfectant is satisfactory for many purposes, nonetheless, where patients have suffered burns or where skin conditions do not permit the spreading of a gel over an area to be treated, there exists a need for an alternate delivery system. That delivery system must be capable of providing disinfectant over an irritated or sensitive area without the pressure required to spread a gel.
In U.S. Pat. No. 2,054,989 to Moore, a semi-solid mass contains alcohol applied to the skin by massaging. The gelling agent used to make the alcohol mass semi-solid may be a soap and a wax. In this semi-solid form the alcoholic composition is dispersed on the skin by rubbing. However, the composition is unsuitable for application to highly sensitive skin.
Alcohol containing moisturizing products dispensed as foams are known, as disclosed in Bennett's The Chemical Formulary, Volume XVI, page 109 (1971), wherein a formulation of a "Fluff-Type Aerosol Moisturizing Cologne" containing 46% alcohol and having a fluorocarbon propellant is recited. The formulation for a Foam-Moisturizing product in The Chemical Formulary, Volume XX, page 194 (1977), includes 35% alcohol, 40% of a 1% solution of Carbopol.RTM.941 (as a thickener) neutralized by diisopropanolamine, and a fluorocarbon propellant. Such alcoholic foaming formulations, however, have concentrations of alcohol lower than the 52% concentration normally required for suitable antimicrobial activity. Additionally, use of fluorocarbon propellants is undesirable for the deleterious effect on the environment and the solubility problems they present.
Mousse-forming compositions can be employed to cleanse skin as taught in U.S. Pat. No. 4,806,262 to Snyder. However, such preparations do not possess the high alcohol content required for antibacterial effect. The alcohol employed in amounts to 5% is used as an emollient and a mousse stabilizer. The propellants used in Snyder, nitrous oxide, carbon dioxide and nitrogen do not form a stable foam in the inventive compositions.
As employed herein the term "mousse" includes a composition which is dispensed as a foam and which remains in that form until mechanically compressed as by rubbing or touching. It is, therefore, necessary to provide a stable foam which will not collapse until subjected to the pressure of a mechanical action. However, the presence of alcohols in high concentration, until now, has often caused foams to collapse.
As noted in U.S. Pat. No. 3,131,153 to Klausner, the use of decreasing amounts of alcohol favors the formation of more stable foams. Klausner in Col. 2, lines 42-45, states that by using decreased amounts of alcohol more stable foams are formed. It is said that if more than 64% alcohol is used, then nonhomogeneous compositions are obtained.
U.S. Pat. No. 3,131,152 to Klausner is referred to in a two-part set of articles by Paul Sanders entitled "Aqueous Alcohol Aerosol Foams." The articles appeared in the Aug. 1966 (pp. 56 ff.) and September 1966 (pp. 57 ff.) Drug and Cosmetic Industry. At page 175 of the Sept. 1966 publication, several formulations from the '152 Klausner patent are recited. Among the compositions listed were an aerosol men's cologne foam containing 53% by weight ethanol and an aerosol rubbing compound containing 59.1% by weight ethanol. The propellants used by Sanders were preferred to be chlorofluorocarbons, although aliphatic hydrocarbons are also disclosed. The solubility characteristics of the chlorofluorocarbons differ from the hydrocarbon propellant used in the present invention. Thus, when using chloroflurocarbons, there is a problem of the incomplete solubility of the combination of surfactants in the aerosol. That results in the possibility of valve clogging and the formation of unstable foams. Further, the '152 Klausner patent does not teach use of a polymeric gelling agent or an amphiphilic nonionic stabilizer with a specific HLB.
A readily-collapsible, antiperspirant sprayable foam composition is taught in U.S. Pat. No. 3,395,214 to Mummert. The composition has 20-60% alcohol and 10-70% water. Cetyl alcohol is employed and an ethoxylated stearyl alcohol is used together with a thickener and antiperspirant. Freon, propane or isobutane were employed as the propellants. However, the surfactants employed in Mummert are not completely soluble with hydrocarbon propellants which results in precipitation thereof and clogged valves when the foam is dispensed.
The Mummert foams also disappear within a few seconds after dispensing and before any mechanical working of the dispensed material. The thickener employed in Mummert was a magnesium aluminum silicate ("Veegum"). It is believed that the undesired "Veegum" together with the surfactant used renders the compositions too unstable and unduly insoluble in the aerosol form.
U.S. Pat. No. 476,273 to Grollier et al. teaches an unstable aerosol foam containing cationic and/or anionic polymers that produce a foam in an aqueous solution. The alcohol content (C.sub.1-8 alcohol) is said not to be more than 50%.
U.K. Pat. No. 1,096,753 to Yardley & Co. Ltd. (equivalent to U.S. Pat. No. 3,824,303) relates to a collapsible foam pre-electric shave lotion. The foam is formed from a 55-70% water:alcohol solution which contains 0.5 to 5% of a surfactant mixture which is an ester or ether of a higher monohydric or dihydric alcohol having eight or more carbon atoms and a higher alcohol. Hydrocarbon propellants can be used. However, the composition does not form a stable foam, lacks a polymeric gelling agent and does not teach the HLB balance of the present invention.
U.S. Pat. No. 4,627,973 to Moran et al. relates to an aerosol skin mousse containing a combination of moisturizers. The alcohol content is only 15-30% by weight.
U.S. Pat. No. 3,770,648 to Mackles is directed to an anhydrous aerosol foam. Mackles Example I4 relates to a hair cleaning foam containing 45% ethanol and only 5% water. A silicone resin is the foaming agent and a fluorocarbon propellant is used. Examples 16 and 17 disclose anhydrous antiperspirant foams containing 74% and 81% alcohol respectively. A silicone resin is the foaming agent and a fluorocarbon propellant is employed.
U.S. Pat. No. 4,440,653 to Briscoe et al. teaches a stable alcoholic foam to be used as a carrier fluid such as a treating fluid for subterranean oil wells. The composition contains a liquid phase of 50-100% alcohol, which may optionally contain water. A nonionic surfactant and thickening agent, such as guar gum, are combined in the alcoholic solution. The liquid is foamed with a gas or mixture of gases such as air, carbon dioxide or preferably nitrogen. The foam-forming gases used in Briscoe are not hydrocarbon propellants. Briscoe fails to employ an amphiphilic nonionic stabilizer or a higher alcohol and a polyethoxylated fatty alcohol. The foam merely functions to stimulate recovery of hydrocarbons (oil) in subterranean formations.
U.S. Pat. No. 4,511,486 to Shah teaches cleaning dentures with an aerated foam. The foamable liquid cleanser includes 1-10% surfactant, 0.1-10% humectant, 25-60% water and 35-70% ethanol or isopropyl alcohol. The foam is non-pressurized. In use the cleaner is forced into an air-mixer to form a foam.
U.S. Pat. No. 4,808,388 to Beutler et al. relates to a foamable cream for the skin which may be in the form of a mousse. Beutler teaches a creamy, oil-in-water emulsion using nitrous oxide or carbon dioxide as the propellant. Alcohols of long-chain fatty acids in concentrations of 0.5-4.5% are employed, but no ethanol or isopropanol is used.
U.S. Pat. No. 4,673,569 to Shernov et al. is directed to a mousse aerosol hair composition having water and alcohol phases. The alcohol phase includes 0.5% to 20% of an alcohol, such as ethanol, as a secondary solvent. The alcohol phase further contains a long-chain nonionic ester and a foam-forming agent. The water phase contains water, a film-forming resin and a corrosion inhibitor. The mousse composition also contains ammonium hydroxide with isobutane as the propellant.
U.S. Pat. No. 3,840,465 to Knowles et al. discloses a foam-producing composition including an aqueous solution of a foam-producing surfactant containing a propellant dispersed therein. The composition further includes a water-insoluble surfactant which is soluble in the propellant. The foam-producing surfactant is a fatty acid salt or synthetic surfactant and the propellant-soluble surfactant is an ethoxylated compound. The composition provides a very persistent foam which is said to last from 40 to 240 minutes. There is no disclosure of high amounts of alcohol being present nor of the collapse of the foam upon being subjected to pressure.